Inverter question (1 Viewer)

Affiliate links here may earn MHF compensation
Oct 27, 2017
1,463
3,371
Perth
Funster No
51,142
MH
Hymer A Class
Exp
Since 2014
I’m not too “hot” on electrons, so this may be a dumb question.

Can an inverter be installed in such a way that it uses the exising van wiring to distribute the 240v to existing sockets, rather than plugging stuff directly into the inverter box. I have an EBL, two leisure batteries, no solar. I am considering a beefy inverter, say 2kw.

Cheers...Keith
 

PeterCarole29

LIFE MEMBER
Jul 23, 2013
1,303
1,400
Colchester
Funster No
27,084
MH
Renault Master Fleetwood
Exp
20 years
yes it could but its too complicated for me to explain what you need to do it.
 
Aug 5, 2018
1,567
3,514
Funster No
55,394
MH
a
yes but the pins on the outside of the vehicle plug would be live when the inverter is on.
You would need to install an auto or manual changeover switch to prevent that.
Also connected to the 240v circuit would be the battery charger, so this would need isolating at the same time other wise it would try charging the batteries because it would think it was on hook up.
Can be wired into the same change over switch mentioned above.
Other than that, yes perfectly feasible and something I am am doing when funds allow.
I had bought some LiFePo4 battery cells from the USA to make up a large battery to power the inverter from but the shipping company refused to post them so to the UK so had to get a refund on that lot. so the project has gone no further currently
 
OP
OP
G-RMPS
Oct 27, 2017
1,463
3,371
Perth
Funster No
51,142
MH
Hymer A Class
Exp
Since 2014
I suppose you could plug a cable into the inverter with the other end plugged into the EHU point, though the battery charging circuit would have to be isolated somehow.
 
Aug 5, 2018
1,567
3,514
Funster No
55,394
MH
a
I suppose you could plug a cable into the inverter with the other end plugged into the EHU point, though the battery charging circuit would have to be isolated somehow.
If the battery locker / inverter locker is close to the EHU point then yep, sounds like a good work around.
Disabling the battery charger "should" be a simple case of pulling the fuse or buying one of those fuse break out leads and fitting a switch into the circuit.

Subscribers  do not see these advertisements

 

Stealaway

Free Member
Jan 8, 2013
8,496
11,541
Dronfield - Derbyshire
Funster No
24,202
MH
Burstner Lyseo 690G
Exp
Happy FLT since 2011
I have two sockets wired separately and permanently plugged into the invertor. Saves any complications and simply switch to existing sockets when on ehu
 
R

Robert Clark

Deleted User
I suppose you could plug a cable into the inverter with the other end plugged into the EHU point, though the battery charging circuit would have to be isolated somehow.
This wouldn’t work as the inverter would then be powering the fridge and possibly the water heater too.

In our van the inverter powers all the sockets. We fitted a Victron inverter / charger which automatically kicks in when the EHU is disconnected.
 
Jan 19, 2014
9,563
25,298
Derbyshire
Funster No
29,757
MH
Elddis Accordo 105
Exp
since 2014
IMAG1027.jpg


You can get these 20a switches on Amazon. Commonly listed as generator changeover switches. Ours is double pole 3 position EHU - off - Inverter.

The charger is always off and I make sure the fridge and water heater are off before going over to inverter. Manual works best for us because I change over to ehu for Ann's hair dryer, plus I don't want a relay or concactor humming away all day. If it's switched over fast the TV doesn't even go off (y)
 

eddie

LIFE MEMBER
Oct 4, 2007
8,279
42,223
Taunton Somerset
Funster No
540
MH
RV
Exp
since 1989
I’m not too “hot” on electrons, so this may be a dumb question.

Can an inverter be installed in such a way that it uses the exising van wiring to distribute the 240v to existing sockets, rather than plugging stuff directly into the inverter box. I have an EBL, two leisure batteries, no solar. I am considering a beefy inverter, say 2kw.

Cheers...Keith
yes very simply.

Locate the wire(s) that lead from the distribution board (trips) to your 13amp sockets put a mains relay in series, with the N/C contacts on the mains input, piggy backed to energise the coil. Connect the N/O contacts to the inverter output

The “load” side of the relay connect to the wire(s) that supply the 13 amp sockets

As you are introducing a potentially lethal power source after the original RCD you must put a secondary RCD in series after the relay
 

pappajohn

LIFE MEMBER
Aug 26, 2007
43,576
51,428
Dark side of the moon
Funster No
172
Exp
Since 2005
Yes, as explained by handyandy in post #3.... But, a 2kw inverter, if used anywhere near its full potential, will hammer your batteries and unless you intend going on hookup the next day you have no real means of topping up the batteries.

If used at its maximum output it will draw 166 amps per hour.
With a pair of 110ah batteries that's around 40 minutes use before the batteries NEED recharging and split charge (driving), your only other charging option, will take many hours.
Consider a smaller inverter and a solar panel or B2B charger.

Subscribers  do not see these advertisements

 
OP
OP
G-RMPS
Oct 27, 2017
1,463
3,371
Perth
Funster No
51,142
MH
Hymer A Class
Exp
Since 2014
Ok, thanks everyone for the guidance. I understand the draw on the batteries, but I was particularly looking for a wiring solution. Probably best to see if I can route an extension lead to somewhere suitable, then I don’t need to bother about technicalities.
 

JeanLuc

Free Member
Nov 17, 2008
3,304
2,199
Warwickshire
Funster No
4,952
MH
Hymer B630 Star-Line
Exp
Since 2007
You said in your first post that you are ‘not too “hot” on electrons’. Unless you are confident about what you plan to do, I would respectfully suggest you get a qualified person to install it for you - such as Vanbitz.
Also, if you really intend to use the full capacity of a 2 kw inverter, you will be drawing something around 175 amps and that will drag down 2 typical leisure batteries in well under an hour. You might get 30minutes if you are lucky (from fully charged).
 

Gellyneck

LIFE MEMBER
Jun 5, 2014
9,884
20,075
Scotland
Funster No
31,836
MH
C Class
Exp
More than toes wet now!
Wasn't it much easier when all we had was a gas mantle \ Tilley lamp and a good book!;):rolleyes::)
Sorry Keef!
 
OP
OP
G-RMPS
Oct 27, 2017
1,463
3,371
Perth
Funster No
51,142
MH
Hymer A Class
Exp
Since 2014
You said in your first post that you are ‘not too “hot” on electrons’. Unless you are confident about what you plan to do, I would respectfully suggest you get a qualified person to install it for you - such as Vanbitz.
Also, if you really intend to use the full capacity of a 2 kw inverter, you will be drawing something around 175 amps and that will drag down 2 typical leisure batteries in well under an hour. You might get 30minutes if you are lucky (from fully charged).

Understood! This is an expensive solution to a daily five-minute hair-drying exercise, with the bonus of charging laptops etc.

Subscribers  do not see these advertisements

 
Last edited:
Nov 6, 2013
3,205
235,947
East Sussex
Funster No
28,906
MH
Hymer B574DL
Exp
Since 2011 (tugger for 20 before that)
Understook


Understood! This is an expensive solution to a daily five-minute hair-drying exercise, with the bonus of charging laptops etc.
Oh yes, many of us have been there :rolleyes:
 
Oct 10, 2009
886
1,910
Bishop's Stortford
Funster No
8,835
MH
Autotrail Delaware
Exp
Since 2011
When we had RoadPro install our inverter they offered two setups. Either an auto switch that gave us 240v on all sockets when on site electric, or separate dedicated sockets. As the inverter comes with two 240 sockets attached we went for just one extra socket next to the microwave so that we can swop the plug over to the inverter when “off grid” and have a multi socket extension permenantly plugged into the inverter. As the inverter is under the bench seat behind the driver’s seat this is not inconvenient.
We decided on this option to protect our habitat warranty.
 

Bart

Free Member
Jun 4, 2016
3,188
1,398
Northern Ireland
Funster No
43,436
MH
Boxer L4H2 van build
Exp
Since 2016
Ok, thanks everyone for the guidance. I understand the draw on the batteries, but I was particularly looking for a wiring solution. Probably best to see if I can route an extension lead to somewhere suitable, then I don’t need to bother about technicalities.
@G-RMPS In our MH I did a per the resource by @Techno which boycott was kind enough to link. And it works great for us.
 
Nov 13, 2013
488
431
Bideford, Devon
Funster No
29,004
MH
Benimar Tessora 487
Exp
since 2011
Had mine set with a selection of 220v sockets 'on' including the A/C. I used to use via EHU but power was grabbed by the fridge, charger etc. Had it sorted by local company
 
Jul 29, 2007
6,582
40,496
Ipswich
Funster No
32
MH
RV and PVC
Exp
30 years
I ran the output from the inverter direct to the electrical locker, so I just plug the ehu into it, battery charger has a switch to turn it off and I can tell the fridge to run on gas, all 7 of the 230v work along with the numerous 110v ones.

Subscribers  do not see these advertisements

 

GPW

Free Member
Feb 23, 2019
606
878
Cambridge UK
Funster No
58,720
MH
Globescout Plus
Exp
Slight to minor!
I’m not too “hot” on electrons, so this may be a dumb question.

Can an inverter be installed in such a way that it uses the exising van wiring to distribute the 240v to existing sockets, rather than plugging stuff directly into the inverter box. I have an EBL, two leisure batteries, no solar. I am considering a beefy inverter, say 2kw.

Cheers...Keith

The main question is:
What do you want to power with the inverter?

2kW from a 12V battery is 2000/12 = 167 Amps, quite a huge load. Also all inverters are not created equal, it really is a case where you get what you pay for, aim for a respected european brand.

The wiring is simpler and better if you replace the van's charger for an 'inverter-charger' such as a Victron unit which does all the EHU monitoring and switching, but it does all get rather complicated, especially if your mains fusebox has more than one circuit on it.

A competent campervan oriented electrician should be able to fit one for you however.
 

Jaws

LIFE MEMBER
Sep 26, 2008
23,869
74,200
Thetford Norfolk
Funster No
4,189
MH
C class, Chieftain
Exp
since 2006 ( I think ! )
Understood! This is an expensive solution to a daily five-minute hair-drying exercise, with the bonus of charging laptops etc.
A little facetious I know, but there is always the option of a towel for hair..and
Laptop chargers that work on 12v ( basically they are a tiny inverter that come with a selection of plugs to fit all sorts of laptops ) for under £20
 

GPW

Free Member
Feb 23, 2019
606
878
Cambridge UK
Funster No
58,720
MH
Globescout Plus
Exp
Slight to minor!
Most stuff is easy for an inverter, but suddenly demanding 2kW while still keeping a decent (high quality waveform and efficient) system gets WAY more complex. First you really have to understand what you are doing and Second - it gets very expensive for any kind of reliability and quality of mains waveform (which some items will demand!).

I'd advise going for a 500VA Victron-Multi Inverter-charger (to replace the existing charger only) and forget about 2kW, as stated above a towel and hairbrush will be fine offgrid, she can always use a hairdryer while on EHU.

That should give you a decent mains performance from a single battery for charging eBikes, laptops, cameras, toothbrushes and running a mains TV etc. Then add 100W-200W of solar for extended off grid days if you need it.
 

tonka

LIFE MEMBER
Jul 2, 2008
10,934
21,866
Cannock, Staffs
Funster No
3,141
MH
A class Burstner 800
Exp
Since 2000
Ok, thanks everyone for the guidance. I understand the draw on the batteries, but I was particularly looking for a wiring solution. Probably best to see if I can route an extension lead to somewhere suitable, then I don’t need to bother about technicalities.

I have a short extension lead from the socket of my inverter and wired to this plug, added the 12v supply off battery at same time. Does the job I need ..

Subscribers  do not see these advertisements

 

Attachments

  • IMG_20190313_192401.jpg
    IMG_20190313_192401.jpg
    79.7 KB · Views: 42
  • Like
Reactions: GPW

two

Aug 4, 2011
4,914
4,588
West Midlands
Funster No
17,624
MH
A-Class Fiat
I’m not too “hot” on electrons, so this may be a dumb question.

Can an inverter be installed in such a way that it uses the exising van wiring to distribute the 240v to existing sockets, rather than plugging stuff directly into the inverter box. I have an EBL, two leisure batteries, no solar. I am considering a beefy inverter, say 2kw.

Cheers...Keith
In simple terms, for simple folk, it cannot be done.
Take a dedicated socket from the inverter.
I'd negotiate a smaller hair dryer, say 1000W (or less) and it will become significantly easier.
 
Apr 27, 2016
7,101
8,360
Manchester
Funster No
42,762
MH
A class Hymer
Exp
Since the 80s
Locate the wire(s) that lead from the distribution board (trips) to your 13amp sockets put a mains relay in series, with the N/C contacts on the mains input, piggy backed to energise the coil. Connect the N/O contacts to the inverter output
I hesitate to question someone so experienced, but shouldn't that be the other way round? When the relay is not energised, you want the inverter to be connected to the sockets, so that's through the N/C contacts. When the relay is energised by the EHU mains, you want the sockets to switch over from the inverter to the EHU mains, so that's through the N/O contacts.
 

eddie

LIFE MEMBER
Oct 4, 2007
8,279
42,223
Taunton Somerset
Funster No
540
MH
RV
Exp
since 1989
I hesitate to question someone so experienced, but shouldn't that be the other way round? When the relay is not energised, you want the inverter to be connected to the sockets, so that's through the N/C contacts. When the relay is energised by the EHU mains, you want the sockets to switch over from the inverter to the EHU mains, so that's through the N/O contacts.
Lol,what did I write?

Just re-read you are right, I am wrong lol

In essence if the relay fails or inverter fails default is back to original
 

PeteH

Free Member
Nov 22, 2007
6,852
9,033
East Riding of Yorkshire
Funster No
900
MH
Rapido, 999M.
Exp
18+yrs plus 25+Towing
I ran the output from the inverter direct to the electrical locker, so I just plug the ehu into it, battery charger has a switch to turn it off and I can tell the fridge to run on gas, all 7 of the 230v work along with the numerous 110v ones.

Not dissimilar to the system I used in the second R-V. But That one had 6 Batteries. and 400W of Solar, and a 220V-50hz x 40W "Smart" charger.

BTW. this site has a section about Inverter usage.: http://www.aandncaravanservices.co.uk/
 

GPW

Free Member
Feb 23, 2019
606
878
Cambridge UK
Funster No
58,720
MH
Globescout Plus
Exp
Slight to minor!
In essence if the relay fails or inverter fails default is back to original

This is the correct DIY method, but a proper inverter-charger does it better. I'll give Victron as an example but all decent brands should do this:

The 500 Multi series will detect if the incoming mains is within the correct safe range before it gets used - so too low or too high and it stops using it.
The 800 and upwards Multi series support Boost and Fade, which means it will re-process mains that is a bit too low or high into the correct voltage so it works exactly as a high-end computer UPS delivering clean power within spec regardless of what goes in!
(The 800 and upwards can also be paralleled for more power with a synchronising bus cable as an aside).

So a relay is fine, but a proper product is always better for the reasons stated above!

Subscribers  do not see these advertisements

 

Join us or log in to post a reply.

To join in you must be a member of MotorhomeFun

Join MotorhomeFun

Join us, it quick and easy!

Log in

Already a member? Log in here.

Funsters who are viewing this thread

Back
Top